1. Technical Field
The present disclosure relates generally to a wound dressing for treating an open wound with a vacuum wound therapy treatment. In particular, the disclosure relates to a dressing having a portal member providing a connection to a vacuum system such that a reservoir over the wound may be evacuated.
2. Background of Related Art
The body's natural wound healing process is a complex series of events beginning at the moment of injury. Initially the body reacts by delivering proteins and other factors to the wound through the blood stream to minimize the damage. Blood clots to prevent blood loss while cells engulf bacteria and debris to carry it away from the wound site. Next, the body begins to repair itself in a stage of healing often referred to as the proliferative phase. This phase is characterized by the deposition granulation tissue in the wound bed. Granulation tissue provides a base structure over which cells may migrate inwardly from the periphery to close the wound. Finally the process ends as collagen gives strength to new tissue over time often forming a scar.
One technique for promoting the natural healing process, particularly, but not exclusively during the proliferative phase, is known as vacuum wound therapy (VWT). Application of a reduced pressure, e.g. sub-atmospheric, to a localized reservoir over a wound has been found to assist in closing the wound. The reduced pressure may be effective to promote blood flow to the area to stimulate the formation of granulation tissue and the migration of healthy tissue over the wound by the natural process. Also a reduced pressure may assist in removing fluids exuding from the wound, which may inhibit bacterial growth. This technique has proven effective for chronic or non-healing wounds, but has also been used in for other purposes such as post-operative wound care.
The general VWT protocol provides for the introduction of an absorbent filler material, such as non-reticulated foams, non-woven fabrics, or gauze, into the wound to absorb exudates. The wound and the absorbent filler material may then be overlaid by a flexible cover layer such as a polymeric film, for example, to establish a vacuum reservoir over the wound where a reduced pressure may be applied by individual or cyclic evacuation procedures. To allow the reduced pressure to be maintained over time, the cover layer may include an adhesive periphery that forms a substantially fluid tight seal with the healthy skin surrounding the wound.
Although some procedures may employ a micro-pump contained within the vacuum reservoir, most VWT treatments apply a reduced pressure using an external vacuum source. Thus, fluid communication between the vacuum source and the reservoir must be established. To this end, a cover layer will often include a connector or portal member to which air hoses from an external vacuum system may be connected.
An aspect of concern in a VWT treatment is the migration of the filler material and wound exudates in the direction of airflow when the reduced pressure is applied. These substances may be deposited on surfaces within a portal member, for example, and over time cause the obstruction or complete occlusion of these portal members. This phenomenon may limit the level of exudate flow from the wound area, or may even prohibit the application of a reduced pressure to the wound area, thus limiting or defeating the effectiveness of the VWT treatment. Accordingly, a need exists for a dressing suitable for use in a VWT procedure.